So I am getting the system is running lean in bank 1 and bank 2. I am going to review the data logs tonight to make sure the car isnt running lean but I know the tune is set to be on the rich side. I replaced all the O2 sensors and my exhaust shop doesnt believe its an exhaust leak but said they would give it a look tomorrow. Anyone have any ideas on Why i would be getting LEAN codes? Here is what OBD-Codes.com has to say....could any of this apply to me? lol http://www.obd-codes.com/p0174 Boost/vac gauge doesnt show anything funny...so maybe i'll have them test the system? and the fuel system has no lack of power i can promise that lol...I am good up to probably 900+ hp with the fuel system I have...and despite my efforts, i dont think im there just yet haha
p0171-fuel system 1/1 lean P0174-FUEL SYSTEM 2/1 LEAN Set Condition:If the PCM multiplies short term compensation by long term adaptive and a certain percentage is exceeded for two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored. Two Trip Fault. Three good trips to turn off the MIL. Possible Causes RESTRICTED FUEL SUPPLY LINE FUEL PUMP INLET STRAINER PLUGGED FUEL PUMP MODULE O2 SIGNAL CIRCUIT O2 RETURN CIRCUIT O2 SENSOR HEATER OPERATION O2 SENSOR MAP SENSOR OPERATION ECT SENSOR OPERATION ENGINE MECHANICAL PROBLEM FUEL FILTER/PRESSURE REGULATOR (HIGH)PCM
Getting plenty of fuel...pressure holds strong at 61psi and no driveability issues. I have seen the MAP sensor thing come up a couple of times and will look tomorrow. I did get the codes down from 6 to just these last 2...but the lean part is what is making me scratch my head lol.
First of all ..... I can't believe you don't have an AFR gauge .... There are a boat load of things. Is it intermittent? Like occassionally you get the codes and then, either 3 cycles later or you clear them and it's good for a while. Or is it just on solid now. You said you replaced the sensors so we can assume you were careful and didn't get contaminants on them? Like did you replace the sensors and THEN started getting the codes. You're swearing by your fuel pressure, fuel system, and injectors so it's not any of them right? A short in either the sensor ground or signal would do that. Any chance of that? Unlikely since it looks like you're getting both banks. How about the connector being loose? Check the PCM harness connector terminals for corrosion or loose. Back to fuel pump, or a restriction...
So.... #1...I do have a A/F gauge...and I have not seen anything that makes me believe that it is running lean, but am going to review datalogs in a little bit to be 2x sure. lol....i know you're the king of monitoring. I have Boost/Vac, A/F, Fuel Pressure, Trans Temp and Volts gauges all for my viewing pleasure. On top of the evic. Have some faith in me Dave LOL. #2 They are solid...i replaced the O2's because of the codes. I (probably dumbly) thought they were getting clogged up from too much carbon from the rich tune i have historically run. But while it did fix the other codes I was getting (O2 slow response, and lean on the down stream O2s) it still left the bank 1 and bank 1 upstream as lean. I was as careful as I could be. I didnt like sterilize my hands or anything lol but I was wearing clean gloves and such. #3 It can never hurt to give the fuel system a look. So I will look into everything. But the fuel system has less than 8,000 miles on it, always uses Mobile 93, and my fuel pressure gauge has never moved from its 61psi reading. So that's why I would say it is unlikely a fuel issue. #4 I plan on having them look over the length of the O2 wiring when they check for exhaust leaks. If there is a short or something hopefully they can find it. I have a lot of faith in the guys I take it to, I just don't want to waste their time (and my money) if I can locate something/fix it lol.
Check the connector to the PCM and the contacts. My bad on the gauges... it's just that I've been traumatized by SOME people here reluctance to gauge up when tuning and getting into serious mods... By the way, the O2's are only monitored in closed loop. I suppose if your tune has changes for part throttle boost it could be that (or lack of) but I think the tune might be low on my list. Closed loop it's trying to cycle back and forth between something like 13.8 and 15.3. constant short term adaptive in one direction or the other will get moved into long term (and short term should be back to starting with no adjustment). Short term can do 25% adjustment and so long term can do 25% (cause short term gets moved into long term). Those percentages are percentages of the base pulse width. [for more you will need to talk to someone technical] I think the base pulse width comes from a table and maybe there are cells for more than one value? The table (PE) for WOT fuel add works that way. I'm not sure throwing the code means you actually went lean... It might be something like both long term and short term are adjusting 80% or something or what they can to keep it around 14:7. So maybe it throws the code before your afr actually goes out of bounds. You'd need to monitor the adaptives. You might log A/F, RPM, Boost, Throttle/Pedal Position, PCM Mode, to see if anything is happening and maybe where.
I think I have all but maybe pedal position logged. I am hoping he will see this lol...maybe i'll shoot him a PM. He got me through it last year with the fouler info. Hopefully he knows some nifty trick to fix the reverse of it as well lol.
Could just be that you're engine is running right now. The code is set when the short and long term adaptives are compared. You have long-term adaptives from bad O2 sensors and short term adaptives from new/good O2 sensors...so their ratio is probably significantly off, hence throwing the code. The PCM doesn't know that hardware was switched. I'd re-load your tune from scratch and log/monitor to see what its really doing.
I actually did reload the tune yesterday. Its still giving me the code. Probably around 150 miles on the car since reloaded the tune. Any idea on how much driving I'd have to do?
by the way dave....PCM is clean (under the hood of my car is cleaner than most peoples interiors lol)....and the connections are all good and snugly in place.
If you're sure the O2s, wiring, and fuel are all good. I think I'd start with the MAP sensor and/or tune.
Yea, but "clean" is different for contacts. You can get a thin layer of oxidation on contacts that you can't even see. You might have bent a pin/contact last time it was plugged in. etc. If you were tugging on the cables when replacing the sensors or whatever, you never know. I believe your long term and short term fuel adaptives adjust (fully) within about 6 seconds after starting the car? The short term adaptives cycle something like 2 times a second. "long term" is relative. Some detail on surrounding conditions? Did it throw the codes before or after some significant event? Like after changing the sensors? or it was throwing the codes before and that's why you changed the sensors. Or you've been working on your tune? Or you did some work under the hood? Or did you do a bunch of stuff and you've been working on a bunch of codes for a while and these are the ones left? Or was everything in a stable state for a while and this just cropped up? Can you clear the code and it reasserts immediately (immediately would be 2 trips)? or does it take a while? Have you tried clearing the codes, starting it up, letting it idle until fully warmed up and then driving it gingerly for a while without going into ANY boost at all? haha, some completely blind speculation... These codes have been there ever since you had the blower and started tuning for it. AFR probably doesn't go out of bounds but there is a lot of compensation going on for part throttle boost. Stevo has it in part throttle boost a LOT.
so doing some live monitoring....we see that under 95% of the driving conditions...i have good a/f.... the only time it runs "lean"...is on a hard downshift where the engine is slowing the car down. its only "lean" for a short time...but i would suppose it has to be the culprit.... I would also imagine this is a tune issue....agree or disagree?
Disagree, that's normal. In fact if you ride down a long enough grade, the PCM will cut all fuel and you'll see 21.00 AFR...scared the crap out of me the first time I saw it. There is an excel program over on lx that CoolVanilla wrote for analyzing your adaptives. I'm totally blanking on the name of it, but you export your log as a (Insert type here) file, then open it in this spreadsheet and it will tell you your adaptives for each cell.
AND THE PLOT THICKENS! with fuel added to the tune, and driving style adjusted................ P0430 - Catalyst System Efficiency Below Threshold (Bank 2) P0420 - Catalyst System Efficiency Below Threshold (Bank 1) P0133 - O2 sensor slow response (Bank 1 Sensor 1)
So you're saying that got rid of the P0171 and P0174? Forget about the cats... you can fiddle with the anti-foulers later. I forgot what generally causes the slow response.
